Improvement in hoisting apparatus



UNITED STATES PATENT OFFICE. f

JOHN G. SHERWOOD, OF BUCYRU `ASSIGrNOR TO HIMSELF AND JAMES ARMSTRONG, OF TOLEDO, OHIO.

IMPRovEMEN-r 1N Hom-rma APPARATUS.

Specification forming part of Letters Patent No. 146,557, dated January 20,1874; application filed November 19, 1873.

To all whom 'it may concern.'

Be it known that I, JOHN G. SHERwooD, of Bucyrus, in the county of Crawford and 'State of Ohio, have invented an Improved impervious to air or moisture, whereby not oiily is any lubrication of the clampingsurface by infiltration prevented, but the atmosphericl pressure causes the clampingsurface tobact as a sucker,77 such as the school-boys well-known plaything, and thus adds greatly both to the lifting power and safety of the apparatus.

In the accompanying drawings, Figure l represents a view in perspective of an apparatus embodying my invention in the best way now known to me, the said apparatus, in this instance, being adapted to grasp an Obelisk. Fig. 2 represents a side elevation thereof, partly in section. Fig. 3 represents a horizontal section on the line x .r of Fig. 1.

Stout beams, blocks, or slabs A, preferably of wood, are strengthened at intervals by horizontal cross-bars B G l), of metal, by preference let into the wood ush with its surface,

and having their ends bent inward and secured to the blocks. strongly secured to these blocks, and to the cross-bars, which they cross at their points of intersection. These straps are provided with rin gs e, to which hoisting-ropes may be secured. Hooks F are likewise secured to these straps, and to" the blocks. The inner face of each block is lined with acontinuous covering or pad, I), of thick gatta-perche. or vulcanized rub-` ber, such, for instance, as that used for heavy belt-ing. This cover or pad is riveted or fastened at its ends to the edges of the block in such manneras to leave anunbroken grasping-surface. The article to be hoisted is clamped between these surfaces or pads by means ot'screw-` bolts Gr, which pass through holes in theblocks on each side ofthe article to be hoisted. These y screw-bolts are provided with clampnuts (1,130 clamp the blocks tightly uponthe article to be hoisted. This clamping expelsthe air from between the rubber surface and that of the stone, and thus greatly increases the power with which the article to be hoisted is grasped. Experience has amply demonstrated the effectiveness of my improved apparatus. l

In a hoisting apparatus, the combination of 'the elastic-pads, the blocks, and the clamping-y screws, snbstantially as set forth. p

Intestimony whereofI have hereunto subscribed my name.

JOHN G. SHERWOOD.

Witnesses:

S. R. HARRIS, JosIAH SCOTT.`

Vertical straps E are likewise y 

